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Wiring Frustrations

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rcufley

rcufley

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I re-veneered and re-finished the dash on my 1980 spitfire 1500. I must say it looks great! I put all the instruments and lights back the way it was prior to removal. After I got it all together and looking good, I started the machine and now the Fuel, Temp and Tach do not work. All the instrument panel lights are working. I spent the last two days under the dash and still can't figure out the problem. Any ideas??
 
The fuel and temp come off one side of the voltage stabiliser, probably marked "I".
The other side of the Voltage Stabiliser (B) comes from the hazard switch (Green Wire), and ALSO goes to the Tach.
Don't think it's grounds, rather, no power.
The temp and fuel ground back through the respective senders.
Key on, test light both sides of the Voltage Stabiliser.
Then, see if the green wire is connected to the hazard switch.
Apparently, Haynes manuals are WRONG.
Save this link:

https://www.triumphspitfire.com/images/wiring/78diagram.jpg
 
Thanks you guy's! I appreciate the feedback and will check the grounds and the voltage stabilizer. Do you think the Voltage Stab could have gone bad?? Oh well, I'll check it out and let you know what I find out tomorrow.... Go Seahawks!!! :smile:
 
Could be....but, since the tach feeds off the power side of the Stabiliser, the tach would work.
I think you don't have power there.
Your brake lights work?
Power from the top fuse feeds the brake light switch and wiper motor and heater fan (green wire) feeds the Hazard switch.
Hazard switch feeds the Voltage Stabiliser and Tach.
Quick check is just to check the Stabiliser first, that way we know where we do and do not have power....unless you have no brake lights, heater fan, or wiper motor.......then look at the fuse, and if a new one blows, you've mis-wired something.
 
I checked another diagram, and, for sure, there are no grounds in the fuel or temp gauges.
Stabilised power in, grounds via the senders.
 
Yup: The fuel and temp gauges get their grounds thru resistance of the respective sending units in order to work. The instrument grounds on them are for lighting only.

<span style="font-style: italic">EDIT: The sending unit wires usually have a black tracer on them to differentiate from power leads.</span>
 
TOC is on the dime with this one. Check the VS conncetions to the two gauges.
 
:iagree:
 
Eureka!!! It all works!! :smile:)
Thanks to everyone for your feedback. And a special thanks to TOC. I used a test light as suggested by TOC and found that not only did I have the simple problem of a blown fuse, but I also had the voltage stab wired backwards. Thanks again for ending my little wiring frustrations. :smile:
 
It's really easier than one thinks.
You just have to THINK like Joe Lucas.

When I was COB on the Soviet Foxtrot we had here for several years, even though I was Qualified Submarines, I found I had to stop and figure out what the engineer's in Mother Russia were thinking (kinda back-engineering), and once I could THINK like them, I could figure out the GROSS STUPIDITY.....oooops..what it was they were doing.
 
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